Distributing valve for pneumatic hammering tools



NOV. 17, 1942. FoRss 2,302,018

DISTRIBUTING VALVES FOR PNEUMATIC HAMMERING TOOLS Original Filed Dec. 30, 1940 V7 yr /A INVENTIOR. ne/r/w; 2 ram:

Patented Nov. 17, 1942 DISTRIBUTING VALVE FOR PNEUMATI HAMlWERING TOOLS Frithiof P..For ss, A urora, Ill., assignor to Independent Pneumatic Tool 00., Chicago, 11]., a corporation of Delaware Original application December 30, 1940, Serial No.

372,227. Divided and this application November 29, 1941, Serial No. 420,960

4 c ai s. (01. 121 19).

This application is a division of my co-pending application Serial No. 372,227 filed December 30, 1940, for distributing valves for portable pneumatically operated hammering tools.

The subject matter of this divisional application is concerned with adapting the distributing valve action of the co-pending application to tools having a barrel and cylinder diameter greater than that of the valve block of thevalve clay diggers. In tools of this character the barrel'marked 41 in Fig. '1 herein is considerably larger in diameter than the barrel of the chipping hammer disclosed in Figs. 1 to 4 inclusive in said co-pending application. This larger barrel increases the diameter of the recess marked 43 at the inner or upper end of the barrel to seat the distributing valve'assembly. v Because of this, the valve assembl is constructed of two action. In this way; the valve action is made 10 interfitting parts as followsz available for thelarger and more powerfulvtools The outer part 49 which seats in the recess in that the adapter mounting supports the valve 48 is in the form of an annulus or ring and block in the larger receiving chamber which the serves as a mounting for the'inner part5!) which larger barrel provides at the inner end of the constitutes the valve block. The valve block 5!] y der- 5 has a radial extension 51- at its inner end to In carrying out the objects of my invention overhang the ring 49 and support the block as disclosed in this divisional application the within the ring as shown in Fig. 1. The handle a apter means surrounds and engages the valve member 53 of the tool is secured to the rear end block and fits within the larger receiving chamof the barrel 4! by side bolts or other desired ber to support the block therein without direct 20 means and seats against the flange 5! on the contact of the block with the chamber as in my co-pending application.

In supporting the valve block in the adapter means, I may provide the valve block with a projecting portion which overlaps the adapter and is engaged by the handle section of the tool on clamping the same to the barrel for securing the adapter and the valve block in place in the tool.

The invention consists further in the features hereinafter described and claimed.

In the accompanying drawing- Fig. l is a fragmentary longitudinal sectional view with parts in elevation of a portable pneumatic clay digger equipped with adistributing valve assembly constituting the subject matter of the present application;

Fig. 2 is a transverse sectional view taken on line 2-2 of Fig. 1;

Fig. 3 is a bottom plan view of the valve and adapter assembly of Fig. l removed from the tool.

Fig. 4 is a cross-sectional view taken through the valve block on line 4-4 of Fig. 2 to illustrate the valve action in its lateral shifting movement; and

Fig. 5 is a perspective view of the cylindric valve member.

In the embodiment of the invention disclosed in the accompanying drawing, the valve action is the same as described .and claimed in the hammering tools as for example, clay spades or 55 block 58 to clamp the latter and the supporting ring 49 in place in the tool.

The handle member 53 is provided with an air supply cavity 54 over the block 50 and this cavity connects with a live air supply passage 55 within the handle unit. This in efiect is similar to the construction employed for the chipping hammer in the co-pending application, it being understood that the handle member 53 is provided with a manually operable throttle valve (not shown) and has means whereby the hose for supplying compressed air to the tool may be connected tothe supply passage 55 as in tools of this character.

The valve block 50 is provided with a bore having'a section lBa of the same design as the bore in the valve block in said co-pending application. This bore mounts a cylindrical distributing valve member 22a similar to the corresponding valve member in the co-pending application. The action of the valve member 22a is the same as that described for the valve member infthe co-pending application and which description is in part repeated herein for clearness in connection with the instant disclosure.

The-plugs 5G, 51 which close the opposite ends ofthe bore [Ba and their receses 58, 59 are uniform in axial dimension. This enables the outer ends of the plugs 56, 51 to be flush with the outer cylindric'surface of the valve block 50 where it fits within the supporting ring 49. In this arrangement, it is not necessary to hold the valve block 50 against rotational displacement within the ring mounting 49 because the ring mounting is constructed to connect the pressure supply passages of the block with the barrel passages in any rotative position of the mounting within the recess 48. This construction will now be described.

As shown in Figs. 1 and 2, the mounting 49 is provided with an annular channel 60 and this channel is connected at a number of points about its circumference with an annular groove 6| in the bottom surface of the mounting 49 by passages 62, 62, The groove 6i faces the bottom of the recesses 48 in which the ring member 49 seats and connects with the several longitudinal passages 63 provided in the barrel 4T as detailed in Fig. 1. The passages 63 are suflicient in number to furnish the desired volume of air to the tool cylinder 52 for reciprocating the piston 65 therein. The passages 63 are connected by a port 66 with the forward end of the cylinder52:

beneath the piston element 65 while one or more passages 64, also in the cylinder 52, are connected by a port 6! with the intermediate part of the cylinder. Port 61 connects with the atmosphere behind an exhaust deflector clip 68 as in tools of this design. Also, as in tools of this character, the passage or passages 64 when drilled through the inner end of the cylinder 52 are closed by a plug 64a as shown in Fi 1 to close the inner end of the passage of the air supply channel 6|.

The valve block 50' is provided with two sets of passages on opposite sides of the valve member 22a in substantially the same manner as in the copending application. The passage 69 which connects the bore [8a with the inner end of the cylinder 52 opens through the bottom surface of the block 59 over said cylinder. The passage 19 connects th opposite side of the bore l8a with the annular channel 60, said channel opening on the inside of the ring mounting 49 as shown. In this arrangement, it is apparent that the passage in the valve block is connected with the channel 60 in any rotative position of the valve block within its mounting 49, and as before stated, the annular groove 61 connects the passages 10 with the barrel passages 63- in any rotative position of the ring 49 in the recess 48. With this arrangement, no keying connection is required and hence production time and machine costs are reduced because there is no need for making a groove in the barrel for either of the plugs 56, 51 as in the form of the disclosure claimed in said co-pending application.

The advantage of the disclosure in Figs. 1 to 3 herein is that the valve action of my invention is adaptable to the larger and more powerful tools in that the mounting 49 makes possible the insertion of the Valve action into tools having a barrel and cylinder diameter greater than the valve block per se.

The bore I8a as in said co-pending application is provided with valve supports 23-, 24 for the valve member 22a and this valve member is hollow and cylindrical as disclosed in said co-pending application and as shown in Fig. 5 herein. The bore l'8a also has valve seats 25, 26 and which valve seats are intersected by the ports 69 and 10, respectively, and are on arcs of the same radius as the valve member 2201.. The bore [8a between the valve supports 23, 24 conforms substantially to the diameter of the valve member 22a and these supports rotatably and slidably mount the valve member within the bore. The bore between the valve seats 25, 26 is wider than the diameter of the valve member whereby the latter may be shifted laterally by the live air pressure supplied to the cylinder through the bore to alternately open and close the ports 69, 10.

The bore [8a is also provided with channels 30, 3|, 32, 33. These channels extend longitudinally of the bore between its recesses 58, 59 and are located between the valve supports 23, 24 and the valve seats 25, 26, respectively. The channels serve to supply pressure fluid to the bore from the inlet ports 38, 39 in any shifted position of the valve member 22a. The inlet ports 38, 39 are provided in the upper portion of the block 50 above the bore Ma. and connect the channels 30, 3| on opposite sides of the valve member with the live air supply cavity 54 in the handle section 3. The channels in being located between the valve supports and the valve seats also serve to localize the areas of the bore at the valve seats to a relatively small portion of the outer circumference of the valve member. This lessens the machining required to fit the valve seats to the valve member.

The piston 65 is connected with a piston rod H which extends out of the barrel 41 at its forward or lower end for connection with the spade or other working element with which the tool is equipped.

The details of construction and arrangement of parts shown and described may be variously changed and modified without departing from the spirit and scope of my invention, except as pointed out in the annexed claims.

I claim as my invention:

1. In a pneumatic hammering tool, a barrel having a cylinder, 9. hammering piston therein, a valve block at one end of the cylinder and having a bore having opposed valve seats and valve supports therebetween, ports connecting the bore at the valve seats to the opposite ends of the cylinder, a cylindrical distributing valve member located within said bore and operable by the fluid pressure supplied to the cylinder through the bore, said valve member being slidably and rotatably supported in the bore by the valve supports for lateral shifting into and out of contact with the valve seats to alternately open and close the ports to reciprocate the piston within the cylinder ,an exhaust for the cylinder inlet ports in the valve block connected to the bore for supplying fluid pressure thereto, and a ring-like element fitting about the valve block for supporting the same within the barrel in operative relation to the cylinder.

2. In a pneumatic hammering tool, a barrel having a cylinder, a hammering piston therein, a valve block at one end of the cylinder and having a bore having opposed valve seats and valve supports therebetween, ports connecting the bore at the valve seats to the opposite ends of the cylinder, a cylindrical distributing valve member located within said bore and operable by the fluid pressure supplied to the cylinder through the bore, said valve member being slidably and rotatably supported in the bore by said valve supports for controlling the reciprocation of the piston within the cylinder by movement of the valve member into and out of contact with the valve seats to alternately open and close said ports, an exhaust for the cylinder, inlet ports in the block connected to the bore for supplying fluid pressure thereto, a ring-like element fitting about the valve block for mounting the same within the barrel over the cylinder, and co-acting means on the block and the ring element for supporting the block therein.

3. A distributing valve assembly for a pneumatic hammer comprising, a valve block having a bore having opposed valve seats and valve supports therebetween, ports in the block at the valve seats, a cylindrical valve member located Within the bore, said valve member being slidably and rotatably supported in the bore by said valve supports, the slidable mounting providing for the lateral shifting of the valve member into and out of contact with the valve seats to alternately open and close said ports, and the rotatable mounting providing for the free bodily turning of the valve member on said supports and seats, closure elements closing the opposite ends of the bore and holding the valve member therein, said block having recesses at the opposite ends of the bore to receive and mount the closure elements therein, inlet ports in the block for the bore, and a member forming a part of the valve assembly and surrounding the block at the closure elements to hold the same in the recesses and providing a support for the valve block Within the barrel of a pneumatic hammering tool.

4. In a pneumatic hammering tool, a barrel having a cylinder, a hammering piston therein, a distributing Valve assembly located at one end of said cylinder and operable by the pressure fluid supplied thereto for reciprocating the piston within the cylinder, said valve assembly having a laterally shiftable cylindrical distributing valve member and a valve block for supporting the same, said cylinder having a diameter at least as large as, the diameter of the valve block, and adapter means for supporting the valve block Within the barrel over the cylinder, said adapter means surrounding and engaging the valve block and seater in a chamber provided in the barrel about the cylinder at the location of the valve block.

FRITHIOF P. FORSS. 

